Malnutrition affects 25% of the children world-wide. In a series of over 40 published papers, we have documented the long-term effects of early protein-calorie malnutrition (PEM) and kwashiorkor in 333 Barbadian children and matched comparison cases from the same socioeconomic backgrounds. Now 30 to 35 years of age, the index children were diagnosed with moderate to severe protein-energy or protein malnutrition during their first year of life after which no further episodes occurred. All previously malnourished children were nutritionally rehabilitated shortly after their illness and were followed by the National Nutrition Centre on a regular basis, until they reached 11 years of age. Birth and postnatal data were available for all children in the study, and they were studied comprehensively throughout their school years (ages five to 18). When compared with controls at 5 to 11 years of age, previously malnourished children demonstrated a striking fourfold increase (15% versus 60%) in the incidence of behaviors associated with attention deficit disorder. Attentional problems at earlier ages predicted poor performance on the Eleven-Plus Examination, the national common entrance exam for high school placement taken by all Barbadian school children at 11 years of age. Attention problems persisted in 50% of the index children up to 18 years of age. Other deficits in the previously malnourished children included reduced IQ scores, soft neurological signs, learning disabilities and impaired social skills. In contrast, physical growth was delayed but showed complete "catch-up" by 16 years of age. To determine whether environmental factors contributed to these findings, socioeconomic conditions and factors in the child's home environment were evaluated at all stages of development, including at the time that malnutrition occurred. Data analyses controlling for these ecological factors confirmed significant independent effects of childhood malnutrition in all cases. In the current study, we propose to extend our studies of this population to their adult years. We plan to evaluate behavioral, cognitive and mental health outcomes, because of deficits documented in earlier years and other long-term studies of prenatal malnutrition, notable the Dutch Famine study, which pointed to the importance of aberrant mental health outcomes in adulthood. Given the availability in Barbados of 98% of our original population and the existence of the comprehensive set of longitudinal data that document their physical and mental development from birth through 18 years of age, we believe a follow-up study of this population in their adult years will make a significant contribution to our understanding of the long-term consequences of postnatal malnutrition on behavioral and mental health outcomes. To our knowledge, there are no other published studies on the adult consequences of postnatal malnutrition in human populations.